[flow] Normalize React.AbstractComponent to the new component type,…

… with best effort flattening

Summary:
We want to one day kill `React.AbstractComponent`, since it's instance targ is not in-line with react 19's model of ref as a prop. People learn what types to write from hover, so it's important that we stop printing out these types.

In this diff, we star to normalize React.AbstractComponent to the new component type, which is enabled regardless of whether component syntax is enabled. We have the following baseline strategy:

1. Props go into `component(...Props)`
2. Instance go into `component(ref: React.RefSetter<Instance>)`
3. Renders go into `component() renders Renders`

For props, we also do some best effort flattening if the props have an object type that we can see in normalizer. For exact objects, it's straightforward; for inexact objects, we add `...{...}` at the end. We bail out on things like getters, methods, etc.

For renders, we won't repeat the `render` keyword if the `Renders` already has a render type.

Changelog: [ide] On hover, values that have `React.AbstractComponent` type will be shown in the [component type](https://flow.org/en/docs/react/component-types/) syntax.

Reviewed By: jbrown215

Differential Revision: D62917950

fbshipit-source-id: 2464a9baf253219ed2dfb90e6ae9dc0bf6b79687

src/common/ty/ty.ml

@@ -77,6 +77,11 @@ type t =
       false_type: t;
     }
   | Infer of symbol * t option
+  | Component of {
+      props: component_props;
+      instance: t option;
+      renders: t;
+    }
   | Renders of t * renders_kind
 
 (* Recursive variable *)
@@ -294,6 +299,21 @@ and utility =
   | ReactCheckComponentRef of t
   | ReactConfigType of t * t
 
+and component_props =
+  | UnflattenedComponentProps of t
+  | FlattenedComponentProps of {
+      props: flattened_component_prop list;
+      inexact: bool;
+    }
+
+and flattened_component_prop =
+  | FlattenedComponentProp of {
+      name: Reason.name;
+      optional: bool;
+      def_locs: aloc list;
+      t: t;
+    }
+
 and renders_kind =
   | RendersNormal
   | RendersMaybe
@@ -580,7 +600,8 @@ class ['A] comparator_ty =
       | InlineInterface _ -> 26
       | Conditional _ -> 27
       | Infer _ -> 28
-      | Renders _ -> 29
+      | Component _ -> 29
+      | Renders _ -> 30
 
     method tag_of_decl _ =
       function
@@ -806,6 +827,7 @@ let mk_exact ty =
   | Tup _
   | InlineInterface _
   | Infer _
+  | Component _
   | Renders _ ->
     ty
   (* Do not nest $Exact *)

src/common/ty/ty_debug.ml

@@ -43,6 +43,7 @@ let string_of_ctor_t = function
   | IndexedAccess _ -> "IndexedAccess"
   | Conditional _ -> "Conditional"
   | Infer _ -> "Infer"
+  | Component _ -> "Component"
   | Renders _ -> "Renders"
 
 let string_of_ctor_decl = function
@@ -387,6 +388,37 @@ struct
           "Infer (%s, %s)"
           (dump_symbol s)
           (Base.Option.value_map ~default:"None" ~f:(dump_t ~depth) b)
+      | Component { props; instance; renders } ->
+        let props =
+          match props with
+          | UnflattenedComponentProps t -> [spf "...%s" (dump_t ~depth t)]
+          | FlattenedComponentProps { props; inexact } ->
+            let props =
+              Base.List.map
+                props
+                ~f:(fun (FlattenedComponentProp { name; optional; def_locs = _; t }) ->
+                  spf
+                    "%s%s: %s"
+                    (Reason.display_string_of_name name)
+                    ( if optional then
+                      "?"
+                    else
+                      ""
+                    )
+                    (dump_t ~depth t)
+              )
+            in
+            if inexact then
+              props @ ["...{...}"]
+            else
+              props
+        in
+        let props =
+          match instance with
+          | None -> props
+          | Some t -> spf "ref: React.RefSetter<%s>" (dump_t ~depth t) :: props
+        in
+        spf "Conditional(%s): %s" (Base.String.concat ~sep:", " props) (dump_t ~depth renders)
       | Renders (t, _) -> spf "Renders (%s)" (dump_t ~depth t)
 
   and dump_class_decl ~depth (name, ps) =
@@ -561,6 +593,40 @@ struct
             ("name", json_of_symbol s);
             ("bound", Base.Option.value_map ~default:JSON_Null ~f:json_of_t b);
           ]
+        | Component { props; instance; renders } ->
+          let props =
+            match props with
+            | UnflattenedComponentProps t ->
+              JSON_Object [("kind", JSON_String "unflattened"); ("type", json_of_t t)]
+            | FlattenedComponentProps { props; inexact } ->
+              let props =
+                Base.List.map
+                  props
+                  ~f:(fun (FlattenedComponentProp { name; optional; def_locs; t }) ->
+                    JSON_Object
+                      [
+                        ("name", JSON_String (Reason.display_string_of_name name));
+                        ("optional", JSON_Bool optional);
+                        ("type", json_of_t t);
+                        ( "def_locs",
+                          JSON_Array
+                            (Base.List.map def_locs ~f:(fun loc -> JSON_String (string_of_aloc loc)))
+                        );
+                      ]
+                )
+              in
+              JSON_Object
+                [
+                  ("kind", JSON_String "flattened");
+                  ("types", JSON_Array props);
+                  ("inexact", JSON_Bool inexact);
+                ]
+          in
+          [
+            ("props", props);
+            ("instance", Base.Option.value_map instance ~f:json_of_t ~default:JSON_Null);
+            ("renders", json_of_t renders);
+          ]
         | Renders (t, variant) ->
           [
             ("argument", json_of_t t);

src/common/ty/ty_printer.ml

@@ -201,6 +201,66 @@ let layout_of_elt ~prefer_single_quotes ?(size = 5000) ?(with_comments = true) ~
               option ~f:(fun t -> fuse [space; Atom "extends"; space; type_ ~depth t]) b;
             ];
         ]
+    | Component { props; instance; renders } ->
+      let to_key x =
+        if property_key_quotes_needed x then
+          let quote = better_quote ~prefer_single_quotes x in
+          fuse [Atom quote; Atom (utf8_escape ~quote x); Atom quote]
+        else
+          identifier (Reason.OrdinaryName x)
+      in
+      let params =
+        match props with
+        | UnflattenedComponentProps t -> [fuse [Atom "..."; type_ ~depth t]]
+        | FlattenedComponentProps { props; inexact } ->
+          let params =
+            Base.List.map
+              props
+              ~f:(fun (FlattenedComponentProp { name; optional; def_locs = _; t }) ->
+                fuse
+                  [
+                    to_key (Reason.display_string_of_name name);
+                    ( if optional then
+                      Atom "?"
+                    else
+                      Empty
+                    );
+                    Atom ":";
+                    pretty_space;
+                    type_ ~depth t;
+                  ]
+            )
+          in
+          if inexact then
+            params @ [Atom "...{...}"]
+          else
+            params
+      in
+      let params =
+        match instance with
+        | None -> params
+        | Some t ->
+          fuse
+            [
+              Atom "ref:";
+              pretty_space;
+              Atom "React.RefSetter";
+              list ~wrap:(Atom "<", Atom ">") ~sep:(Atom ",") [type_ ~depth t];
+            ]
+          :: params
+      in
+      let renders =
+        match renders with
+        | Renders _ -> type_ ~depth renders
+        | t -> fuse [Atom "renders"; space; type_with_parens ~depth t]
+      in
+      fuse
+        [
+          Atom "component";
+          list ~wrap:(Atom "(", Atom ")") ~sep:(Atom ",") ~trailing:false params;
+          space;
+          renders;
+        ]
     | Renders (t, variant) ->
       let renders_str =
         match variant with

src/common/ty/ty_serializer.ml

@@ -182,15 +182,98 @@ let type_ options =
     | TypeOf (FunProto, _) -> just (qualified2 "Object" "prototype")
     | TypeOf (ObjProto, _) -> just (qualified2 "Function" "prototype")
     | TypeOf (FunProtoBind, _) -> just (qualified3 "Function" "prototype" "bind")
-    | Renders (t, kind) ->
-      let argument = type_ t in
-      let variant =
-        match kind with
-        | RendersNormal -> T.Renders.Normal
-        | RendersMaybe -> T.Renders.Maybe
-        | RendersStar -> T.Renders.Star
+    | Component { props; instance; renders = renders_ } ->
+      let all_params =
+        match props with
+        | UnflattenedComponentProps t ->
+          let rest_param =
+            {
+              T.Component.RestParam.argument = None;
+              annot = type_ t;
+              optional = false;
+              comments = None;
+            }
+          in
+          { T.Component.Params.params = []; rest = Some (just rest_param); comments = None }
+        | FlattenedComponentProps { props; inexact } ->
+          let params =
+            Base.List.map
+              props
+              ~f:(fun (FlattenedComponentProp { name; optional; def_locs = _; t }) ->
+                let name =
+                  let x = Reason.show_name name in
+                  if Ty_printer.property_key_quotes_needed x then
+                    let quote = Ty_printer.better_quote ~prefer_single_quotes:false x in
+                    let raw = quote ^ Ty_printer.utf8_escape ~quote x ^ quote in
+                    Ast.Statement.ComponentDeclaration.Param.StringLiteral
+                      (Loc.none, { Ast.StringLiteral.value = x; raw; comments = None })
+                  else
+                    Ast.Statement.ComponentDeclaration.Param.Identifier (id_from_string x)
+                in
+                let annot = annotation t in
+                just { T.Component.Param.name; optional; annot }
+            )
+          in
+          let rest =
+            if inexact then
+              Some
+                (just
+                   {
+                     T.Component.RestParam.argument = None;
+                     annot =
+                       just
+                         (T.Object
+                            {
+                              T.Object.exact = false;
+                              inexact = true;
+                              properties = [];
+                              comments = None;
+                            }
+                         );
+                     optional = false;
+                     comments = None;
+                   }
+                )
+            else
+              None
+          in
+          { T.Component.Params.params; rest; comments = None }
       in
-      just (T.Renders { T.Renders.operator_loc = Loc.none; argument; comments = None; variant })
+      let all_params =
+        match instance with
+        | None -> all_params
+        | Some t ->
+          let ref_prop =
+            just
+              {
+                T.Component.Param.name =
+                  Ast.Statement.ComponentDeclaration.Param.Identifier (id_from_string "ref");
+                optional = false;
+                annot =
+                  just
+                    (mk_generic_type (id_from_string "React.RefSetter") (Some (mk_targs [type_ t])));
+              }
+          in
+          let params = ref_prop :: all_params.T.Component.Params.params in
+          { all_params with T.Component.Params.params }
+      in
+      let params = just all_params in
+      let renders =
+        match renders_ with
+        | Renders (t, kind) -> T.AvailableRenders (Loc.none, renders t kind)
+        | _ -> T.AvailableRenders (Loc.none, renders t RendersNormal)
+      in
+      just (T.Component { T.Component.tparams = None; params; renders; comments = None })
+    | Renders (t, kind) -> just (T.Renders (renders t kind))
+  and renders t kind =
+    let argument = type_ t in
+    let variant =
+      match kind with
+      | RendersNormal -> T.Renders.Normal
+      | RendersMaybe -> T.Renders.Maybe
+      | RendersStar -> T.Renders.Star
+    in
+    { T.Renders.operator_loc = Loc.none; argument; comments = None; variant }
   and generic x targs =
     let id = id_from_symbol x in
     let targs = Base.Option.map ~f:type_arguments targs in

src/services/autocomplete/autocompleteService_js.ml

@@ -129,6 +129,7 @@ let lsp_completion_of_type =
   | Utility _
   | IndexedAccess _
   | Conditional _
+  | Component _
   | Infer _
   | Renders _ ->
     Lsp.Completion.Variable

src/typing/ty_members.ml

@@ -302,6 +302,7 @@ let rec members_of_ty : Ty.t -> Ty.t member_info NameUtils.Map.t * string list =
   | Utility _
   | IndexedAccess _
   | Conditional _
+  | Component _
   | Infer _
   | Renders _ ->
     (NameUtils.Map.empty, [])

src/typing/ty_normalizer.ml

@@ -783,15 +783,35 @@ module Make (I : INPUT) : S = struct
         let%bind config = type__ ~env config in
         let%bind instance =
           match instance with
-          | ComponentInstanceOmitted _ -> return Ty.Void
-          | ComponentInstanceAvailable t -> type__ ~env t
+          | ComponentInstanceOmitted _ -> return None
+          | ComponentInstanceAvailable t -> type__ ~env t >>| Base.Option.some
         in
         let%bind renders = type__ ~env renders in
-        return
-          (generic_talias
-             (Ty_symbol.builtin_symbol (Reason.OrdinaryName "React$AbstractComponent"))
-             (Some [config; instance; renders])
-          )
+        let props =
+          let props_flattened =
+            match config with
+            | Ty.Obj
+                {
+                  Ty.obj_def_loc = _;
+                  obj_literal = Some false | None;
+                  obj_props;
+                  obj_kind = (Ty.ExactObj | Ty.InexactObj) as obj_kind;
+                } ->
+              Base.List.fold_result obj_props ~init:[] ~f:(fun acc -> function
+                | Ty.NamedProp { name; prop = Ty.Field { t; polarity = _; optional }; def_locs; _ }
+                  ->
+                  let prop = Ty.FlattenedComponentProp { name; optional; def_locs; t } in
+                  Ok (prop :: acc)
+                | _ -> Error ()
+              )
+              |> Base.Result.map ~f:(fun props -> (props, obj_kind = Ty.InexactObj))
+            | _ -> Error ()
+          in
+          match props_flattened with
+          | Ok (props, inexact) -> Ty.FlattenedComponentProps { props = List.rev props; inexact }
+          | Error () -> Ty.UnflattenedComponentProps config
+        in
+        return (Ty.Component { props; instance; renders })
       | DefT (_, RendersT (InstrinsicRenders n)) -> return (Ty.StrLit (OrdinaryName n))
       | DefT (r, RendersT (NominalRenders { renders_id = _; renders_name; _ })) ->
         let symbol =

tests/autocomplete/autocomplete.exp

@@ -5723,7 +5723,10 @@ Flags: --pretty
 {
   "result":[
     {"name":"ab","type":"number"},
-    {"name":"ac","type":"React$AbstractComponent<Props, any, React$Node>"}
+    {
+      "name":"ac",
+      "type":"component(ref: React.RefSetter<any>, ...Props) renders React$Node"
+    }
   ]
 }
 

tests/autocomplete_react/autocomplete_react.exp

@@ -387,7 +387,7 @@ Flags: --pretty
   "result":[
     {
       "name":"AbstractComponent",
-      "type":"type AbstractComponent<-Config, +Instance = mixed, +Renders: React$Node = React$Node> = React$AbstractComponent<Config, Instance, Renders>"
+      "type":"type AbstractComponent<-Config, +Instance = mixed, +Renders: React$Node = React$Node> = component(ref: React.RefSetter<Instance>, ...Config) renders Renders"
     },
     {
       "name":"ChildrenArray",